Chapter: 1MULTIMEDIA ELEMENTS

MUTIMEDIA APPLAICATION

What is Multimedia

• Derived from the word “Multi” and “Media”Multi• Many, Multiple Media• Medium• Multiple means by which information is stored,

transmitted, presented or perceived.• E.g. text, photographs, maps, sound, video etc.

Definition of multimedia• Multimedia is a combination information in

the form of text, graphic, sound, animation, and video that is delivered interactively to the user by electronic means.

TEXT

AUDIO

GRAPHIC

VIDEO

ANIMATION

Color

Charts

Voice

Sound Effect Music

Maps

Photographs

Type faces

Motion Pictures

Animation

Goals & Objectives

• Re-engineering of existing application.• Interactive tools• Open solutions (portable).• Bidirectional communication.• To produce cost effective solutions.• More work in less time.• Centralized information.

•TEXT Example

•GRAPHICS Example

•AUDIO Example

•ANIMATION example

Multimedia System

• System capable of processing multimedia data and applications.

• Characteristics:– Must be computer controlled.– Integrated components.– Information must be represented digitally.

• Components:– Computer system, commn. n/w, display devices,

capture devices, storage devices.

Limitation of Traditional Input Device• Keyboard most common input device

– evolution simple , numeric alphanumeric and multifunction

• GUI pointing device mouse or pen– essential for selecting and moving graphical objects.

• Traditional multimedia variety of other types of input.• Only Text initially no measure of quality normal dot

matrix printer • high quality of text, text color, text attributes advanced

printer like laser printer.• Data inputs like audio or voice, full motion video, still

photos and images etc require special device like digital pens ,video cameras , image scanners

Digital v/s Analog

• Need to convert analog to digital.– E.g. scanning image

• For full-motion video and audio, most i/p devices produce analog while computer can process only digital. (e.g. microphone)

• Coding & Decoding process.• Hardware devices and software programs that

perform this function are called codecs.– It includes compression and decompression algos.

Pen Input• An input device that allows the user to point, write, draw

and gesture.• Gesture allows user to select and act upon the object.• Features:

– Natural device for unskilled or partly skilled person.– Can be used as a pointing device.– Small in size– Can be used for palmtop computers (PDAs), notebooks etc.– Allows adding annotations to forms and documents.

The digital pen captures and stores writing.The writing is sent via USB or Bluetooth

Digital Pen

Light Pen Structure

Light Pen

• Light pen input device used with CRT display to point at items on the screen or to draw new items or modify existing ones.

• The light pen had a photo sensor at the tip.• Photo sensor o/p amplified shaped fed to

flip flop whose status is (set)• Whenever status flip flop is !comp is

interrupted and reads coordinates of points where light is touched on screen

Uses of light pen

• Can use instead of keyboard to request further info

• Provide quick response to operator inquiry

• Used as input device in CAD application

• Write and sketch on the screen of CRT

Image Scanner

• Types of scanner:– Flatbed Scanner– Sheet fed Scanner– Drum Scanner– Hand held Scanner

Flatbed Scanner

Sheet fed Scanner

Hand held Scanner

Working of Scanner

Musical Instrument Digital Interface (MIDI)

• Protocol that enables computer, synthesizers, keyboards and other musical device to communicate with each other.

• Has been widely accepted and utilized by musicians and composers.

• 16 channels of information, each of which can be routed to a separate device.

• MIDI messages are unidirectional.• An extra sound cable is necessary for 2-way

communication.• No error detection capability.• Max cable limit is 15 meter

• MIDI connector• MIDI ports

– IN– OUT– THRU (allows data to be forwarded to another instrument)

• Multiply devices can be connected in a daisy chain maner

• MIDI components:– Channel– Voice– Sequencer (storage server / s/w music editor)– Synthesizer– Track– Pitch

• MIDI Message

Status byte Data byte

Data byte 1 Data byte 2

Channel number and Function to be performed

Additional parameter

Additional parameter

• Classification of MIDI messages

MIDI messages

Channel messages

Voice messages

Mode messages

System messages

Common messages

Rea-time messages

Exclusive messages

• Channel Messages:– Applied to specific channel– Channel number is included in the status byte for these messages– Classified into:

• Voice Messages:– Carry musical performance data– Instruct the receiving instrument to assign particular sounds to its voice

• Mode Messages:– Affects the way the receiving instrument responds to incoming channel voice

messages

• System Messages:– Not channel specific, affect the system as a whole, e.g. timing signal for

synchronization.– No channel number is specified in their status byte– Classified into:

• Common Messages:– Intended for all receivers in the system

• Real-Time Messages:– related to synchronization– To synchronize all of the MIDI clock-based equipments within a system, like

Sequencer.• Exclusive Messages:

– Related to things that cannot be standardized, like patch parameters or sample data

Video Display Technology• Display Terminologies:

– Triad– Pixel– Drift (image moves up in a very slow motion)– Jitter (image jumps at high rate)– Swim (a sort of shadow image move from top to

bottom)– Convergence– pincushioning

Block diagram of a CRT monitor

Monochrome CRT

Construction of LCD

Working of LCD

Printers• Types of printers:– Dot Matrix– Ink Jet– Laser

Ink Jet Printer

Laser Printer

Multimedia Elements

1. Facsimile • first practical means of transmitting document images

over a telephone line.• The basic technology, now widely used, has evolved to

allow higher scanning density for better-quality fax.• standardized at a very early stage to CCITl Group 3

compression standards (RLL). • Typical pixel densities used for facsimile are in

the 100 to 200 dpi (pixels/inch) range.

Document images • used for storing business documents that must be

retained for long periods of time or may need to be accessed by a large number of people.

• Removes the need for making several copies of the

original for storage or distribution.• Usually 300 dpi• For gray scale or color, the sizes are larger to

accommodate the color information.– Normally 400 dpi

Geographic information system maps (GIS) • being used widely for natural resource and

wildlifemanagement.

• Two kinds of technologies are used for storage and display of geographic maps.

• Raster storage allows a map to be displayed on agraphical display system just like any other GUIapplication

• applications consist of road maps and area maps (used to track natural resources).

• Attribute data is assigned and identified, usually by map

coordinates.

• Another application combines raster images that have thebasic color map and a vector overlay showing the railroads or highways and other human-made structures, and textdisplay showing attributes of features in the map.

• Full-motion Stored and Live Video• Holographic Images• Audio messages• Video messages

Holographic image

Multimedia Applications

• Document Image• Image Processing and Image Recognition

– Image recognition– Image enhancement– Image reconstruction– Image animation– Image annotation

• Optical Character Recognition (OCR)• Handwriting Recognition• Full Motion Digital video applications• Electronic Messaging

Multimedia Systems Architecture

APPLICATIONS

Graphical User Multimedia Interface Extensions

O.S. Software MultimediaDrivers Driver Support

System hardware Add-on multimedia(Multimedia-enabled) devices and peripherals

Fig: Multilevel architecture based on interface bus

Application Application

Application compatibility

Layer

SystemsCompatibility

Layer

Hardwarelayer

Application compatibility

Layer

SystemsCompatibility

Layer

Hardwarelayer

Network File Server

Analogdevices

Analogdevices

Multimedia Interface bus

Object file serverWAN

CD-ROM

LAN

Jukebox

Multimedia Data Interface Standards• Earliest and simplest formats used were:

– Intel’s DVI (Digital Video Interface)– Apple’s Quicktime– Microsoft’s AVI (Audio Video Interleave)

• Intel’s DVI– Processor-independent specification for video interface

• Apple’s Quicktime– Designed by Apple computers, to support multimedia applications– Capable of handling various formats of digital videos, pictures,

sounds, panoramic images.– Video file formats

• QuickTime movie (mov), MPEG-2,4 , AVI, 3GPP

– Audio file formats• iTunes audio, MP3, WAV, AMR.

• Microsoft AVI:– Offers low-cost, low-resolution video processing– Suitable for average desktop users

Storage Media• Primary Storage Media:

– Temporary storage– Types: RAM, ROM, PROM, EPROM, EEPROM

• Random Access Memory:– Temporary storage– Programs can be loaded from outside and executed.– Larger the RAM better the performance.– Volatile memory.– Stores data and instructions that are frequently used by the

CPU.– Instructions in RAM constantly changes, depending on the

need of the CPU.– Types:

• DRAM and SRAM.

• ROM– Contains inst. Which are activated each time the computer is turned

on.– ROM inst. Performs POST check.– Instruction can not usually be changed.– Instructions are built into the electronic circuits of the chips.– non-volatile.– Access to info is random.

• Programmable Read Only Memory (PROM)– Not economically feasible.– Are blank ROM that can be programmed using special programming

apparatus.– Suitable for development work.– Not programmed during manufacturing but are custom programmed

by the user– One time programmable– More flexible and convenient than ROM.